A number of printers, copiers, and multi-function products may utilize at least one print head that is fluidly coupled to an ink supply. Such a print head typically includes a plurality of nozzles having corresponding ink ejection actuators, such as heater elements.
A print head can typically be carried across a print medium while the ink droplets are discharged onto selected pixel locations. Ink droplets are typically discharged from the nozzles onto a print medium by actuating associated heater elements or heaters. A fire pulse is typically supplied to a heater for a period of time in order to discharge an ink droplet from a nozzle. An approximate amount of desired energy for properly ejecting an ink droplet is typically associated with a print head heater. This approximate energy is provided by supplying a fire pulse over a period of time.
The manufacture of print heads may involve certain manufacturing tolerances resulting in manufacturing variation, including variations in the sheet resistance of the material used in heater elements, mask alignment variations, variations in the rise and fall times of transistors that drive the heater elements, and variations in the voltage level of a power source. These manufacturing variations and other variables often affect the period of time that the fire pulse should be supplied in order to properly eject an ink droplet.
Conventional systems may attempt to optimize the energy sent to a print head heater by repeatedly printing a pattern using different fire pulses and then scanning the pattern to determine which of the fire pulses will deliver the optimal energy to the print head nozzles. These conventional systems, however, may often test a broad range of potential fire pulses that take into account the numerous manufacturing variations that are applicable to any given print head. Such testing typically utilizes a relatively large amount of ink in initializing a print head. Additionally, given the broad range of potential fire pulses that are examined, the conventional testing may not identify an optimum fire pulse with a high degree of accuracy.
Accordingly, there is a need for systems and apparatus for optimizing energy supplied to a print head heater.